The use of accurate position information of a mobile station, such as cellular or other wireless communication devices, is becoming prevalent in the communications industry. The satellite positioning system (SPS), such as the Global Positioning System, offers an approach to providing wireless mobile station position determination. A SPS user can derive precise navigation information including three-dimensional position, velocity and time of day through information gained from satellite vehicles (SVs) in orbit around the earth. The signals that are received from the SVs are typically weak. Therefore, in order to determine the position of a mobile station, the SPS receiver must be sufficiently sensitive to receive these weak signals and interpret the information represented by them.
One limitation of current SPS receivers is that their operation is limited to situations in which multiple satellites are clearly in view, without obstructions, and where a good quality antenna is properly positioned to receive such signals. As such, they normally are unusable in areas with blockage conditions, such as where there is significant foliage or buildings or other obstacles (e.g., urban canyons) and within buildings.